Additional chromosome in a child as a result of a balanced reciprocal translocation t(12;18)(p13;q12) in his mother's karyotype

In this case report we present a child with an additional chromosome in the karyotype. The karyotypes of the boy and his parents were analyzed by use of a conventional banding technique (GTG) and fluorescence in situ hybridization (FISH). Probes painting whole chromosomes 12 and 18 were used in FISH. Cytogenetic examination of the parents revealed that his mother was carrying balanced reciprocal translocation between chromosomes 12 and 18. Her karyotype was described as 46,XX,t(12;18)(p13;q12). Father's karyotype was normal, described as 46,XY. The boy's karyotype was defined as 47,XY,+der(18)t(12;18)(p13;q12). The additional chromosome appeared probably due to 3:1 meiotic disjunction of the maternal balanced translocation, known as tertiary trisomy. The mother displayed a normal phenotype and delivered earlier a healthy child. However, the boy with the unbalanced karyotype shows multiple congenital abnormalities.     

10p- Syndrome associated with multiple chromosomal abnormalities

Summary A karyotype with six de novo autosomal abnormalities in chromosomes 2, 4, 9, 10, 12, and 13 was identified in a 7-year-old boy with mental retardation and other minor malformations. The G-and C-banding techniques revealed an equilibrated translocation between autosomes 2 and 4 and between autosomes 9 and 13. One chromosome 10 has lost genetic material from its short arms, probably because of an interstitial deletion. An unidentified chromosomal fragment has become inserted in the long arms of an autosome 12. The G bands demonstrate that genetic material inserted in the autosome 12 is not the genetic material deleted from the autosome 10.The propositus presents clinical features similar to the reported cases with 10p-syndrome. Nevertheless it is not possible to establish the influence of the genetic material inserted in autosome 12 on the propositus' phenotype.     

Interstitial deletion of the long arm of chromosome 7 46,XX,del(7)(pter→q2200::q3200→qter)

Summary We present a boy with the karyotype 46,XY,r3 and a phenotype with psychomotor and growth retardation, craniofacial anomalies, syndactyly of the toes, and edema of the feet. The karyotypes and phenotypes of both parents are normal.     

Trisomy 9p with an isochromosome of 9p

An 18 1/2-year-old female is described with moderately severe mental retardation, the phenotype of the trisomy 9p syndromy, and an isochromosome for the short arm of a chromosome 9, contained in an unique karyotype, 46,XX,-9,t(7q9q),+ iso 9p.     

A case of insertional translocation resulting in partial trisomy 16p

This report concerns the case of a boy with partial trisomy 16p resulting from the insertional translocation of the short arm of chromosome 16 into the long arm of chromosome 1 in his father. He was referred for genetic testing because of mental retardation, short stature, microcephaly, seizures and multiple dysmorphic features. Chromosome analysis performed in the child demonstrated the presence of additional material in the long arm of chromosome 1. Paternal high resolution chromosome analysis and fluorescence in situ hybridisation revealed the following karyotype: 46,XY,ins(1;16)(q42;p13.1p13.3), while the karyotype of the boy is 46,XY,der(1),ins(1;16)(q42;p13.1p13.3)pat. This is the first reported case of partial trisomy 16p due to paternal insertional translocation.     

Boy with seizures (West syndrome) and distal 7q duplication syndrome due to an unbalanced 7q;9p translocation

We report a 15 month old boy with prominent metopic suture, epicanthal folds, strabismus, low-set ears, microretrognathia, large anterior fontanel, bilateral simian creases, muscular hypotonia, and severe psychomotor retardation. He also had West syndrome. An electroencephalogram showed hypsarrythmia, and cranial MR indicated a myelinisation delay. Standard karyotyping showed additional material on one chromosome 9p. Using FISH, a terminal 7q duplication spanning 26 Mb in size and a terminal 9p deletion sized (at least) 9.1 Mb were identified. The father had a karyotype of t(7;9)(q33;p23) and the mother's karyotype was normal. The boy presented typical facial features of the distal 7q duplication syndrome but no genital anomalies attributable to his distal 9p deletion. We assume that the severe epilepsy is likely due to the trisomy 7q.     

Deletion of long arms of chromosome 13.

The case is presented of a girl with the banded karyotype 46,XX,del(13)(q22) and a phenotype of severe mental and growth deficiency, mongoloid slant of palpebral fissures, ptosis, hypertelorism, microcephaly, microstomia, micrognathia, nystagmus, gothic palate, uvula fissa, low-set malformed ears, short fingers, pedes excavati, dislocation of hips and diabetes insipidis. Both parents have a normal phenotype and karyotype.     

Growth retardation, distinct oriental-like facies, glaucoma, brachydactyly, ventricular septal defect and speech disorder. An unknown entity.

A caucasian boy with distinct oriental-like facies, short stature, brachydactyly, congenital ventricular septal defect, glaucoma, and speech disorder is reported. Routine laboratory tests, karyotype, and hormonal profile (IGF 1, growth hormone during provocative testing, thyroid hormones, prolactin, gonadotrophins) were normal. Radiologic skeletal survey did not disclose any abnormality. Both parents were apparently normal, but short in stature.     

Hereditary motor and sensory neuropathy (HMSN) IA, developmental delay and autism related disorder in a boy with duplication (17)(p11.2p12)

We present a 6-year-old boy with moderate developmental delay, gait disturbance, autism related disorder and mild dysmorphic features. He was seen for evaluation of his retardation since the age of 2.8 years. At first sight, a cytogenetic analysis showed a normal 46,XY karyotype. Neurological examination at the age of 5.5 years revealed a motor and sensory polyneuropathy. A quantitative Southern blot with probes PMP22 and VAW409 specific for Charcot-Marie-Tooth type 1 (CMT1) disclosed a duplication which confirmed the diagnosis HMSN Ia. Subsequently, GTG banded metaphases were re-evaluated and a small duplication 17p was seen on retrospect. Additional FISH with probe LSISMS (Vysis) specific for the Smith-Magenis region at 17p11.2 again showed a duplication. Both parents had a normal karyotype and the duplication test for CMT1 showed normal results for both of them. The boy had a de novo 46,XY,dup(17)(p11.2p12) karyotype. The present observation confirms previous findings of mild psychomotor delay, neurobehavioural features and minor craniofacial anomalies as the major phenotypic features of dup(17)(p11.2) and dup(17)(p11.2p12); in cases of duplications comprising the PMP22 locus HMSN1 is associated. A recognizable facial phenotype emerges characterized by a broad forehead, hypertelorism, downslant of palpebral fissures, smooth philtrum, thin upper lip and ear anomalies.     

Partial 1p monosomy in a physically and mentally retarded boy

An 8-year-old boy is reported with marked mental and physical retardation, microcephaly, hypertelorism, mongoloid palpebral fissures, hypoplasia of the maxillary portion of the face, and other discrete anomalies. Deletion of the distal portion of the short arm of the chromosome 1 and the karyotype 46,XY, del(1)(p33----pter) was detected.     

Trisomy 20pter»q11 in a malformed boy from a t(13;20)(p11;q11) translocation-carrier mother

Summary A 31-year-old boy revealed moderate motor and mental retardation, normal growth, a congenital heart defect and multiple minor dysmorphic signs and anomalies including brachycephaly, orbital hypotelorism, upward slanting palpebral fissures, short and beaked nose, full cheeks, malformed auricles, hypoplastic external genitalia, rocker-bottom feet with prominent heels, and various minor radiologic anomalies of bones. An extra chromosome in his karyotype appeared to represent trisomy of the short arm of chromosome 20 due to a maternally inherited balanced t(13;20)(p11;q11) translocation.     

A craniosynostosis in a boy with a del(7)(p15.3p21.3): assignment by deletion mapping of the critical segment for craniosynostosis to the mid-portion of 7p21

Summary A tiny interstitial delection of 7p was found in a 5-month-old boy with a craniosynostosis and many anomalies. His karyotype was 46,XY,del(7)(p15.3p21.3). Here we present not only further evidence of an association between craniosynostosis and 7p monosomy, but also deletion mapping to indicate that the critical segment for craniosynostosis lies in the mid-portion of 7p21, that is at 7p21.2 or the proximal part of 7p21.3.     

Xp22.3; Yq11.2 chromosome translocation and its clinical manifestations

We report clinical and molecular investigations in a boy with karyotype 46,Y,der(X)t(X;Y)(qter-->p22.3::q11.21-->qter) and his mother with karyotype 46,X,der(X)t(X;Y)(qter-->p22.3::q11.21-->qter). Haplo-insufficiency for the Xp22.3-->pter chromosomal region in the boy resulted in postnatal growth retardation, developmental delay, partial ichthyosis and facial dysmorphism, but normal external genitals. His mother has a normal phenotype with normal stature and gonadal function but borderline intelligence. FISH-analysis showed a duplication of the Y-heterochromatin probe in the proband and a deletion of the Y933D4 probe in his mother. Molecular investigations situated the Xp22.3 breakpoint between DXS278 and the KAL gene and the Yq11.21 breakpoint between the DYS391 and DYS390 in the proband and his mother. X-inactivation study was performed by analysis of the polymorphic CAG-repeat in the androgen-receptor gene as described showing a normal random (40% versus 60%) inactivation pattern in the mother. The manifestations in male and female with loss of the Xp22.3-->pter and gain of the Yq11.21-->qter chromosomal region are discussed.     

Interstitial deletion of the band 4p15.3 defined by sequential replication banding

A 15-year-old boy with intellectual disability was found to have a de novo interstitial deletion in the short arm of chromosome 4. Using GTL banding and sequential replication banding the deleted band was found to be the more terminal of the two G dark sub-bands of 4p15, that is 4p15.3. The karyotype was defined as 46,XY,del(4)(p15.2p16.100). To our knowledge this specific deletion has not been previously described.     

De novo ring chromosome 3 in a girl with hypoplastic thumb and coloboma of iris

We describe a female child with a ring chromosome 3, found after investigation for short stature. Her karyotype was 46,XX,r(3)(p26-q29). Her phenotype mainly differs from that of the nine patients previously reported with ring chromosome 3, by the presence of hypoplastic right thumb and bilateral coloboma of the iris.     

Transverse testicular ectopia with abnormal karyotype - a case report

OBJECTIVES: Growth disturbances and developmental malformations of external genitalia, such as hypospadias, bifid scrotum and micropenis, coexisting with non-palpable testes, may develop as a result of primary endocrinological dysfunctions as well as an effect secondary to chromosomal aberrations. Therefore, patients with these symptoms require specific diagnostic and therapeutic approaches. Design and methods: We present an example of TTE as a presentation of karyotype abnormalities. Clinical presentation - 9.5 year old boy presented with hypospadias, bilateral cryptorchidism and right inguinal hernia and short stature. Results: Endocrine test showed low testosterone levels with adequate gonadal response. Laparoscopy was performed and revealed the presence of TTE. Conclusions: The presence of mosaic karyotype with abnormal Y chromosome does not exclude a possibility of testis migration disorders, including TTE, caused by other (possibly genetic) factors. Laparoscopy is a technique of choice for diagnosis and treatment in cases of cryptorchidism.     

Complex rearrangement involving 9p deletion and duplication in a syndromic patient: genotype/phenotype correlation and review of the literature

We describe a 7-year-old boy with a complex rearrangement involving the whole short arm of chromosome 9 defined by means of molecular cytogenetic techniques. The rearrangement is characterized by a 18.3 Mb terminal deletion associated with the inverted duplication of the adjacent 21,5 Mb region. The patient shows developmental delay, psychomotor retardation, hypotonia. Other typical features of 9p deletion (genital disorders, midface hypoplasia, long philtrum) and of the 9p duplication (brachycephaly, down slanting palpebral fissures and bulbous nasal tip) are present. Interestingly, he does not show trigonocephaly that is the most prominent dysmorphism associated with the deletion of the short arm of chromosome 9. Patient's phenotype and the underlying flanking opposite 9p imbalances are compared with that of reported patients and the proposed critical regions for 9p deletion and 9p duplication syndromes.     

Two new cases of the Christchurch (Ch1) chromosome 21: evidence for clinical consequences of de novo deletion 21P-

We performed an investigation of two unrelated cases with extremal variants of chromosome 21 without visible materials of the short arms (Christchurch or Ch1 chromosome). In the first case chromosome 21p- was initially detected during routine cytogenetic amniocentesis. Chromosomal variant was inherited from phenotypically normal father to phenotypically normal fetus (phenotypically normal boy after the birth). The second case of chromosome 21p- was detected in 7 years old boy, referred to cytogenetic analysis due to mental retardation and mild congenital malformation, including prenatal hypoplasia, microcephaly, low-set dysplastic ears, short nose, micrognatia, short neck. Molecular characterization of 21p-variant chromosomes was performed by the use of FISH with DNA probes specific to the short arm and centromeric region of chromosome 21 (telomeric, beta-satellite, ribosomal, classical satellite and alphoid DNA probes). Chromosomes 21p-hybridized positively only with telomeric DNA at both chromosomal ends and alphoid DNA probes at centromeric region of the first patient. In second case (de novo deletion of 21p), the Ch1 was associated with clinical phenotype and loss of telomeric and subtelomeric DNA in the p-arm of chromosome 21. Therefore, the complete absent of the short arm of chromosome 21 may be considered as abnormal. We propose that de novo deletion 21p- could have negative consequences due to absence of large portion of chromosomal DNA from the p-arm (telomeric, satellite or ribosomal DNAs) and following imbalance in organization and functioning of genome.     

Are some multiple congenital anomalies with mental retardation (MCA/MR) the clinical expression of rare autosomal fragile sites?

A boy with MCA/MR and a fragile site (FS) at 8q22 opens the discussion of a possible association between a rare autosomal FS and an abnormal phenotype. The child was born after prenatal diagnosis of ureterohydronephrosis. He had facial dysmorphia and mental retardation (IQ = 40). The karyotype showed 8q22 FS in 12% of the cells obtained after addition of FUdR to the culture medium. No other etiologic factor was shown to be responsible for the MCA/MR syndrome. Several authors have reported a variety of neurodevelopmental abnormalities and mental retardation in individuals with rare FS expressed on chromosomes 2, 9, 10, 16 and 19. If rare FS predispose to phenotypic abnormalities what are the mechanisms?     

Pure partial trisomy 5q33-->5q35 resulting from the adjacent-1 segregation of a paternal (5;14)(q33;p12) translocation.

A 14-year-old male was referred for evaluation of mental retardation with short stature and dysmorphic features. His karyotype was 46,XY,der(14)t(5;14)(q33;p12)pat, resulting in a pure partial 5q33-q35 trisomy due to the adjacent-1 segregation of a paternal balanced translocation. Paternal blood karyotype revealed a balanced translocation t(5;14)(q33;p12) retaining Ag-Nors. To date, only two cases of pure partial 5q trisomies spanning this region have been reported. Analysis of these cases and the one we report does not allow the delineation of a specific phenotype.